When generating SHA2 checksums with `openssl`, we want to give
preference to the newer OpenSSL that might have been installed with
Homebrew. However if there's no `brew` command the ERR trap will kick in
and display the "BUILD FAILED" notice although the build would proceed
to run.

Related: c0dc8908

Fixes #713

Handles output like:

    Picked up JAVA_TOOL_OPTIONS: -javaagent:/usr/share/java/jayatanaag.jar
    java version "1.8.0_31"

Fixes #710

Fix JRuby 9.0.0.0-pre1 definition

Add JRuby 9.0.0.0.pre1

Upgrade openssl-1.0.1l

mruby 1.1.0 was released

See the [annoucement](http://www.mruby.org/releases/2014/11/19/mruby-1.1.0-released.html).

Upgrade openssl-1.0.1k

Closes #664, closes #682

Prior to this we tried to use pre-built LLVM binaries since Yosemite,
but starting with Rubinius 2.3.0 this is no longer a feature of its
build system. Instead, look for "llvm" Homebrew package and suggest
installing it if it's missing.

Add Ruby 2.3.0 dev definition

Closes https://github.com/sstephenson/ruby-build/issues/689.

Added definition of Ruby 2.2.0

add jruby-1.7.18

Add definition of Ruby 2.2.0-rc1

Final dist filename change for JRuby 9000.

Add jruby-1.7.17

http://www.jruby.org/2014/12/09/jruby-1-7-17

Highlights:
  56 issues fixed for 1.7.17
  native crypt()
  Fixed bad encoding of string interpolated within backticks
  popen2+ now works properly with env hash
  improvements to align MRI and JRuby FFI
  updated stdlib to 1.9.3p392 (+ rexml security fixes)
  tzdata updated

JRuby 1.7.16.2 has been released to address CVE-2014-8090.  All users
are encouraged to upgrade

http://jruby.org/2014/12/08/jruby-1-7-16-2.html

Added definition of 2.2.0preview2